A CDN (content delivery network) is a network of edge servers that delivers your site's files from a location close to each visitor.
A CDN is a group of servers spread across many cities, all holding copies of your website's files. When a visitor loads your site, the CDN serves images, scripts and often whole pages from the server nearest to them, instead of making every request travel to your hosting server.
Say your site is hosted in Europe and someone visits from Sydney. Without a CDN, every file crosses the world and back. With one, most files come from a server in Australia, so the page loads noticeably faster.
How a CDN works
- You point your domain at the CDN, usually by changing your nameservers or adding a CNAME record.
- A visitor requests a page, and the request goes to the nearest CDN edge server.
- If the edge server has a fresh copy in its cache, it sends it straight away.
- If not, it fetches the file from your hosting server (called the origin), sends it to the visitor and keeps a copy for the next person.
The CDN decides how long to keep each file based on caching headers and its own settings.
Benefits of using a CDN
- Faster load times for visitors far from your server, through shorter distances and fewer network hops.
- Less load on your hosting, because the CDN handles most requests for static files.
- Lower bandwidth use on your hosting account.
- Protection against traffic floods and some attacks. Many CDNs include a WAF and DDoS mitigation.
- Better resilience, since cached pages can sometimes still be served if your origin is briefly down.
Do you need a CDN
If most of your visitors are in one country and your host is nearby, a CDN gives a smaller speed boost, although the security features can still be worth it. If you have visitors across several continents, sell online, or serve lots of images and video, a CDN usually makes a clear difference. Many CDNs, including Cloudflare, offer a free plan that's enough for most small sites.
Common CDN problems
- Old content showing: purge the CDN cache after updates.
- Redirect loops with SSL: set the CDN's SSL mode to fully encrypted when your host already has a certificate.
- Broken admin areas or carts: exclude logged-in and checkout pages from CDN page caching.
- Wrong visitor IPs in logs: your server sees the CDN's IP unless it's configured to read the real one from headers.
AblePage works with Cloudflare and other CDNs on every plan, alongside free SSL and LiteSpeed on the server side.